Re: 3.3V-5V level ****fters

On Thu, 25 Sep 2008 04:02:49 +0100, Eeyore
<rabbitsfriendsandrelations@[EMAIL PROTECTED]
> wrote:

>
>
>Martin Riddle wrote:
>
>> "Joerg" <notthisjoergsch@[EMAIL PROTECTED]
> wrote in message
>> news:hVACk.1362$Ws1.1079@[EMAIL PROTECTED]
>> > What's the jelly-bean level ****fter du jour, the most popular?
>> >
>> > Need to ****ft three sigs 3.3V to 5V and another three 5V to 3.3V.
>> > Stuff us analog dudes normally don't do. The TXB0104 looks ok, so
does
>> > the 74LVC4245. But the specs for both are horrible, incomplete at
>> > best. Not much in drive levels mentioned, or just for one direction.
>> >
>> > The topper is a comment in the TXB spec, "OE should be tied to GND
>> > through a pulldown resistor; the minimum value of the resistor is
>> > determined by the current-sourcing capability of the driver" That
>> > driver is obviously on the chip. Duh! Of course they also forgot what
>> > to do if not needed. Pull up? Leave open? Who knows. Well, maybe they
>> > had a kegger the night before ...
>> >
>> > Here's what seems to qualify as a datasheet these days:
>> > http://focus.ti.com/lit/ds/symlink/txb0104.pdf
>> >
>> > VOH and VOL at 20uA. Microamperes! Couldn't believe it.
>> >
>> > --
>> > Regards, Joerg
>>
>> I third the LV parts, should be fine either direction.
>> I vaguely remember something about Fairchild's tiny logic too.
>
>Single gates on a chip you mean ? Have you seen the prices they charge
for
>them !
>
>Graham

My inventory re****t is showing parts from 12 cents to 44 cents each,
depending on quantity purchased and function. There are plenty of
times when being to plop down 1 or 2 gates somewhere is real handy. 

NL37WZ16 is a remarkable part for 27 cents. It's a fierce, sub-ns edge
rate triple buffer/driver in a US8 package. It easily violates US
ex****t restrictions for fast pulse generators.

John